Generally, catheters are a kind of medical devices which hold a stent and transfer it to a target location, that is, a lesion, to be treated.
Such a catheter is used to transfer a stent to a lesion. In detail, after the stent is installed on the catheter, it is transferred to the lesion by the catheter. Thereafter, the catheter releases the stent towards the lesion. Then, the stent forcibly pushes the lesion portion, which has blocked a portion of an inner cavity, outwards so that space can be secured in the inner cavity, thus enabling the flow of not only blood but also endocrine secretions such as bile.
A representative example of conventional catheters for stent surgery was proposed in Korean Patent Laid-open Publication No. 10-2010-0086294.
The conventional catheter for stent surgery functions to move a stent along a guide wire towards a lesion portion on which stenosis has occurred or is in progress. The catheter includes an outer tube part, a movable tube part and a stent part. The outer tube part includes an outer tube which is connected to a handle body and has an outlet hole through which the guide wire comes out of the outer tube. The movable tube part includes a movable tube which is connected to a front end of a push rod which is inserted into the outer tube through the handle body of the outer tube part. The movable tube has therein an outlet hole through which the guide wire comes out of the movable tube. The stent part includes an installation tube in which a stent disposed on the front end of the movable tube of the movable tube part is installed while being reduced in volume. A rear end of the installation tube is partially inserted into a front end of the outer tube.
This conventional catheter further includes a cylindrical-tube-shaped reinforcing member which is coupled to the outer tube and encloses the outer circumferential surface of the outer tube in such a way that the outlet hole of the outer tube is exposed to the outside so as to prevent a part of the outer tube that defines the outlet hole from being bent during surgery. The reinforcing member has a wire hole through which the guide wire comes out of the reinforcing member.
The conventional catheter having the above-mentioned construction is configured to reduce the length of the guide wire. As the length of the guide wire is reduced, handling in setting a guide direction is facilitated, and the production cost can be reduced.
However, the conventional catheter for stent surgery has a problem in which when the guide wire which moves forwards or backwards through the outlet hole of the outer tube is inserted into the outer tube, it may make contact with the inner tube and become entangled with the inner tube, whereby the guide wire may not be smoothly moved forwards or backwards.
As such, in the conventional catheter, because the guide wire may make contact with the inner tube or become entangled with it, the guide wire cannot be reliably moved to the target location that an operator wants, thus making the stent surgery difficult.